1972 4-speed

[D S.]

Is there an identifying tag or some characteristic on the exterior of the 4-speed transmissions that one can immediately tell if it is an M21 or M22?

Thanks,
Scott Sims
Texas Chapter

[Joe L.]

Re: 1972 4-speed

Is there an identifying tag or some characteristic on the exterior of the 4-speed transmissions that one can immediately tell if it is an M21 or M22?

Thanks,
Scott Sims
Texas Chapter

Scott------


Yes, if it's a Muncie manufactured after October, 1968. There will be a suffix code after the manufacturing code of either "A", "B", or "C". "A"= M=20, "B"=M-21, and "C"= M-22. For 70-74 Muncies, a drain plug does NOT necessarily indicate an M-22.

Of course, any suffix code only tells you what was ORIGINALLY in that case and not necessarily what's in it now.

[Joe L.]

Re: 1972 4-speed

[QUOTE=Roy Vazquez (48911);632004
Also, I read, take a drive with a passenger, If you can have a conversation with him, you have a M21, if you can't hear him, you have a M22 (because of the whine)
Regards
Roy[/QUOTE]

Roy-----


M-22 gear noise is nowhere near loud enough to interfere with normal, in-car conversation.

[Richard F.]

Re: 1972 4-speed

If you are always trying to get into 4th gear as soon as you can because of the gear whine, it's probably an M-22.

[William C.]

Re: 1972 4-speed

If original to the car, chances are about 5% it's an M-22, and the stamped ID code on the case is the Key.

[Wayne M.]

Re: 1972 4-speed

,..... if it's a Muncie manufactured after October, 1968. There will be a suffix code after the manufacturing code of either "A", "B", or "C". "A"= M=20, "B"=M-21, and "C"= M-22. For 70-74 Muncies, a drain plug does NOT necessarily indicate an M-22.

Of course, any suffix code only tells you what was ORIGINALLY in that case and not necessarily what's in it now.

Here's an example of a late 1969 Camaro from the Norwood assy. plant. Assembled two days after the letter suffixes started, on Oct 21st (P9R21x) [ x = per codes mentioned above].